Slagging furnace



May 20, 1941. J. VAN BRUNT ETAL SLAGGING FURNACE Filed June 5, 1959 MMLIZVEAiTORS;

A TTORNE YS.

Patented May 20', 1941 2,242,491 'SLAGGING FURNACE John Van Brunt,Flushing, N. Y., and Albert C.

Weigel, East Orange, N. J., assignors to Combustion Engineering Company,Inc., New York, N. Y., a corporation of Delaware Application June 5,1939, Serial No. 277,380

6 Claims.

This invention relates to improvements in bottom constructions ofslagging furnaces and particularly to bottoms of tubular construction inwhich liquid slag discharges through an opening in the bottom.

One of the primary objects of our invention is the provision ofimprovements in the construction and arrangement of the cooling tubes ofsuch bottoms.

More specifically, it is one of the objects of our invention to providean improved arrangement of the tubes of such tubular bottoms which formthe boundary of the slag discharge opening.

Another object of our invention is to provide an arrangement of thetubes of the bottom by means of which any desired level of the slag bedmay be obtained in a very simple manner.

Other objects have to do with the manner of connecting the bottom tubesinto the circulation of the boiler which is associated with the furnace.

How the foregoing, together with such other objects and advantages asmay hereinafter appear, or are incident to our invention, are realized,is illustrated in preferred form in the accompanying drawing, wherein-Figure 1 is a fragmentary sectional elevational view of the lowerportion of a slagging furnace embodying our invention;

Figure 2 is a fragmentary plan view taken on the line 2-2 of Figure 1;

Figure 3 is an enlarged fragmentary crosssectional view taken on theline 3-3 of Figure 1;

Figure 4 is a fragmentary view of a modification of the invention; and

Figure 5 is an enlarged cross-sectional view illustrating anothermodification of the invention.

In the drawing we have illustrated the lower portion of a combustionchamber A of a boiler and furnace installation, the bottom B of which isconstructed in accordance with our invention. The front, rear and sidewalls are provided with upright steam evaporating tubes 6, l and 8,respectively, and burner means C for the introduction of fuel, such aspulverized coal, are provided, these being located in this case at thecorners'of the combustion chamber for vortical firing.

The front, rear and side wall tubes 6, I and 8 are connected at theirlower ends into bottom headers 9, Ill and II, respectively, and at theirupper ends for delivery into steam space of the boiler.

The bottom B comprises a plurality of closely spaced water tubes l2connected at one end into the header 9 and at the other end into theheader [0, and a plurality of tubes l3, in this instance two, which areconnected at one end into the header 9 and, as shown in Figures 1 and 2,are bent upwardly at their other ends to extend along the rear wall withthe tubes 1.

A header l4 having a downcomer connection [5 with water space of theboiler is provided to supply water to the furnace tubes, there beingconnections l6 from this header to the header 9 and connection I! to theside wall headers ll, it being pointed out that a header II and sidewall tubes 8 similar to those shown in Figure l are employed at the nearside wall as well as at the far side wall shown.

The bottom tubes 13 referred to are bent upwardly at I8 so that they liein a plane somewhat above the plane of the remaining bottom tubes l2,and they are bowed at I9 to form a liquid slag discharge opening 20extending through the bottom. The bowed portions of these tubes definethe periphery of the opening 20 so that a cooled lip is provided overwhich the discharging liquid slag flows. As illustrated in Figure 2,certain of the tubes [2 are also bowed in the region of this opening.

The bottom tubes are provided with longitudinally extendingsubstantially abutting fins 2| for closing the spaces therebetween. Itis to be noted that the fins 22 of the tubes l3 and of the adjacenttubes of the set of tubes l2 are disposed at an angle, as clearly shownin Figure 3, because of the elevation of the tubes l3 above the level ofthe tubes l2. The tubes I 3 are also provided with longitudinallyextending radially disposed fins for retaining refractory material 23 atthe lip of the opening.

The bottom tubes are provided with a lining or covering 24 of refractorymaterial and, as shown in Figure 3, this covering is of a thickness suchthat its top surface is flush with the refractory material 23 at the lipof the opening. It is to be understood, however, that this covering maybe made of less thickness so that a bed of liquid slag may be maintainedon the bottom, if desired.

The particular arrangement of raising the tubes forming the boundary ofthe slag opening is advantageous in that the level of liquid slag in thefurnaces is thereby raised above the top of the headers 9 and I0 intowhich the bottom tubes are connected. Through this novel arrangement alevel of the bed of liquid slag at any desired level may be obtained bymerely altering the amount that the tubes l3 are raised above the levelof the tubes l2.

In the modification illustrated in Figure 4 we have shown the coolingtubes l3a, which correspond to the tubes l3 above described, connectedinto an outside header 25 from which upcomer tubes 26 lead to steamspace of the boiler.

In Figure 5 we have shown a modification in which the end header Illa,which corresponds to the header I0 above described as having a bent orupwardly curved portion 2'! into which the raised cooling tubes l3b forthe slag opening are connected. All of the uprightsteam evaporatingtubes 1 of the rear wall are connected into this header lOa.

We claim:

1. In a. bottom for slagging furnaces having a liquid slag dischargeopening extending therethrough, the combination of cooling tubesextending across said bottom in closely spaced relation and lying in ahorizontal plane, end headers into which the ends of said cooling tubesare connected, a pair of similarly extending tubes the major portions ofwhich lie in a horizontal plane spaced above the plane of said firstmentioned tubes and headers, said pair of tubes being'bowed to provide aperipherally cooled lip for said liquid slag discharge opening, finsonsaid first mentioned tubes substantially closing the spacestherebetween and angularly disposed fins on said pair of tubes and thetubes adjacent thereto for substantially closing the spacestherebetween, and refractory covering for said tubes for pre ventingliquid slag from passing through said bottom except at saidopening'.

2. In a furnace for, burning slag forming fuel, the combination of acombustion chamber, and a bottom for said chamber having a liquid slagdischarg opening extending therethrough com prising spaced water tubesextending across said bottom in closely spaced relation and lying in ahorizontal plane, a pair of similarly extending tubes the majorportionsof which lie in a plane above the plane of said firstmentionedtubes, said pair of tubes being bowed to provide a peripherally cooledlip for said slag discharge opening, upright steam evaporating tubes ata wall of said combustion chamber, and a water compartment into whichone end of said pair of tubes are connected to receive water, the otherend of said pair of tubes being connected to said upright steamevaporating tubes;

3. In a furnace for burning slag forming fuel, the combination of acombustion chamber and a bottom for said chamber having a liquid slagdischarge opening extending therethrough, comprising spaced water tubesextending across said bottom in closely spaced relation, certain of saidtubes being raised abov the level of the remaining tubes and havingbowed portions providing a cooled lip for said liquid slag dischargeopening, said certain tubes having upwardly bent portions extendingalong a wall of said combustion chamber to constitute steam evaporatingtubes thereat.

4. In a furnace for burning slag forming fuel, the combination of acombustion chamber and a bottom for said chamber having a liquid slagdischarge opening extending therethrough, comprising spaced water tubesextending across said bottom; in closely spaced relation, certain ofsaid tubes being raised above the level of the remainiiig tubes andhaving bowed portions providing a cooled lip for said liquid slagdischarge opening, a downcomer header into which said bottom tubes areconnected at one end, and a header into which the other ends of saidtubes are connected, said last mentioned header having an upraisedportion into which said raised tubes are connected.

5. In a bottom for slagging furnaces having a liquid slag dischargeopening extending therethrough, the combination of substantiallyhorizontally disposed cooling tubes extending across said bottom inclosely spaced relation, means closing the spaces between said tubes,end headers into which the ends of said tubes are connected, a pair ofsimilarly extending tubes, the major portions of which lie in asubstantially horizontal plane above the plane of said first mentionedtubes and headers, said pair of tubes being bowed to provide aperipherally cooled lip for said liquid slag discharge opening, andmeans closing the spaces between said pair of tubes and the adjacenttubes of said first mentioned tubes.

6. In a bottom for slagging furnaces having a liquid slag dischargeopening extending therethrough, the combination of substantiallyhorizontally disposed cooling tubes extending across said bottom inclosely spaced relation, end headers into which the ends of said tubesare connected, a pair of similarly extending tubes, the major portionsof which lie in a substantially horizontal plane above the plane of saidfirst mentioned tubes and headers, said pair of tubes being bowed toprovide a peripherally cooled lip for said liquid slag dischargeopening, and refractory covering for said tubes for preventing liquidslag from passing through said bottom except at said opening.

JOHN VAN BRUN'I. ALBERT C. WEIGEL.

